Method for producing a three-dimensional component

ABSTRACT

A method for producing a three-dimensional component by means of a laser melting process, in which the component is produced by consecutively solidifying individual layers made of building material by melting the building material, wherein said building material can be solidified by the action of radiation, wherein the melting area produced by a punctiform and/or linear energy input is detected by a sensor device and sensor values are derived therefrom in order to evaluate the component quality. The sensor values detected in order to evaluate the component quality are stored together with the coordinate values that locate the sensor values in the component and are displayed by means of a visualization unit in two- and/or multi-dimensional representation with respect to the detection location of the sensor values in the component.

This application is a Divisional of U.S. application Ser. No.13/812,446, filed Jan. 25, 2013 which was a U.S. 371 National Stageentry of International Application Serial No. PCT/DE2011/001088 filedMay 19, 2011 which claims priority to German Application No. 20 2010 010771.7 filed Jul. 28, 2010. The contents of each of these applicationsare hereby incorporated herein by reference in their entirety as if setforth verbatim.

BACKGROUND OF THE INVENTION

The present disclosure relates to a method for producing athree-dimensional component by a laser melting process, in which thecomponent is produced by successive solidification of individual layersof building material which can be solidified by the action of radiation,by fusing the building material, having the further features of thepreamble of claim 1.

Moreover, the present disclosure also relates to a device for carryingout this method and to the use of a visualization apparatus fortwo-dimensional or multidimensional, preferably 2D or 3D, representationof component regions of components produced in generative fashion by theaction of radiation on powder-like building material in respect of thecomponent quality thereof.

DISCUSSION OF RELATED ART

WO 2007/147221 has disclosed a device and a method for monitoring andfor controlling a selective laser melting construction process. Theillustrated device for selective laser powder processing comprises abuild platform with a powder bed, a powder deposition system forapplying a powder surface to the build platform, a laser, the focusedlaser beam of which impinges on the powder surface and causes the powderto melt within a melt zone. The laser beam is guided over the powdersurface by means of a scanner device. Moreover, provision is made for adetector for capturing electromagnetic radiation which is emitted orreflected by the powder surface and interacts with an optical systemthat follows the laser beam and is suitable for guiding the radiation inthe direction of the detector.

The detector of the known device is embodied such that it can capturethe electromagnetic radiation emitted or reflected by a moveableobservation region on the powder surface, wherein the moveableobservation region is greater than the minimum laser spot of the laserbeam. As a result, it is possible to capture the melt pool created inthe powder bed.

The detector can be used to establish the size of the melt zone, inparticular the length and width and a length-to-width ratio. Moreover,it is possible to select specific parts of the electromagnetic spectrumof the radiation emitted by the melt pool.

SUMMARY

In accordance with the present disclosure there is provided a methodhaving the features of the preamble of claim 1 and an associated devicefor carrying out the method such that the values captured thereby can beevaluated more easily. This object is achieved by virtue of the factthat sensor values captured for evaluating component quality are storedtogether with coordinate values localizing the sensor values in thecomponent and are displayed by means of a visualization apparatus in a2D or 3D representation in respect of the capture location thereof inthe component.

In other words, the object is achieved by virtue of the fact that thesensor values captured for evaluating the component quality are storedtogether with the coordinate values localizing the sensor values in thecomponent and are displayed by means of a visualization apparatus intwo-dimensional and/or multidimensional representations in respect ofthe capture location thereof in the component. The sensor device is ableto operate, preferably in respect of the dimensions, shape and/ortemperature of the effects of the point- and/or line-shaped energyinflux detected in the melt region.

In a preferred embodiment, sensor values of a component plane aredisplayed in the case of a 2D representation, which sensor valuescorrespond to a layer which is solidified by the action of radiationfrom a new deposition of building material. In particular, it isadvantageous if sensor values of a freely selectable component sectionalplane are displayed in the case of a 2D representation, which planeextends at an angle (e.g. at right angles or at an angle less than30°)to a layer successively solidified by the action of radiation. Inparticular, the sectional plane can be freely selectable both in termsof its angle and in terms of its position within the fictitiousinstallation space on the screen of the visualization apparatus, similarto what is also the case in commercially available 2D/3D CAD computerprograms.

Furthermore, it is advantageous if in the case of a two-dimensionaland/or multidimensional representation only sensor values are displayedvisually and/or highlighted which represent component regions which,compared to at least one definable (predefined) intended degree ofsolidification or intended temperature value or intended density value,have a deviating, more particularly reduced, degree of solidification ortemperature value or density value. It is likewise possible, in additionto the degree of solidification, the temperature value and the densityvalue, also to use an intended energy influx and/or intended melt pooldimensions as a basis for displaying the deviation and/or highlighting.

By way of example, these regions can be highlighted by a targetedselection of different colors, grayscale values, degrees of transparencyand/or in respect of an areal structure (shading type such as dotted,respectively obliquely ruled at different angles, etc.).

Furthermore, the coordinate values localizing the sensor values in thecomponent can, at least in part, be the component coordinates used toproduce the component. It is likewise possible to position or localizeor assign the sensor values to a coordinate value both by means of usingthe build coordinate values (the information underlying the buildingprocess) and, exclusively or additionally, by means of usinglocalization sensors detected during the building process by means offurther sensors.

In a further advantageous embodiment, coordinates are assigned to thesensor values by means of exposure data or scanner data. Additionally,or as an alternative thereto, it may also be advantageous if during theareal capture of the whole build plane or the section comprising thecomponent cross section the coordinates of a radiation energy influx ofthe component plane are captured and assigned to the sensor values andthe position of the component plane (Z coordinate) is capturedseparately.

These days, visualization apparatuses are used in conjunction with X-rayand computed tomography technology and generally serve to display sensorvalues which are captured metrologically as a result of the namedmethods in an existing, i.e. present in the completed state, body.

The visualization method and an associated visualization device(software) of the present disclosure are implemented in conjunction witha generative production process and are used to display values capturedin the melt pool during the building process in a more effective fashionin order, directly after the completion of and/or still during thebuilding process, to provide an operator of such a laser meltingapparatus with information as to whether the solidified component layerssatisfy the requirements placed on the component in respect of fusion,temperature profile, work piece solidity, etc. Should a componentproduced in generative fashion be found not to be solid enough and at alater date give rise to a user complaint, then e.g. archived,build-historic visualization information can be used to check veryquickly whether e.g. a breakpoint of the tool was in actual factproduced according to the design specifications or whether there wereupward or downward deviations (e.g. in tolerance ranges). It is possibleto check, particularly if fine structures are present within thecomponent, whether the degree of fusion, the temperature profile afterheat reductions, the component density and the like were set in such afashion there that breakage should be avoided. For future buildingprojects, such insight can be used to avoid work piece breakage and/ormaterial failure.

When claim 1 refers to a two-dimensional or multidimensionalrepresentation, this means either that a two-dimensional image of thevisualized sensor values is displayed, with the sensor values lying in asectional plane, e.g. a component plane, or in a plane extending at anangle to the build plane, or that in the case of a 3D representation thecomponent is displayed in virtually transparent fashion and adjustmentsof the component quality are illustrated on the basis of the establishedsensor values and the coordinate values, e.g. build coordinate values,correlated thereto.

In a development of the method, it is possible in the case of a 2D or 3Drepresentation only to visually filter out sensor values which representcomponent regions which, compared to a definable intended degree ofsolidification, have a deviating, more particularly reduced, degree ofsolidification. Naturally, the same also applies to representations ofe.g. the melt temperature, the density and the like.

In the process, an optimized value can be displayed in a first color, afirst grayscale value and/or with a first areal structure and valuesdeviating upward or downward from this optimized value are displayeddifferently in terms of color, grayscale value and/or in respect of theareal structure (e.g. the type of shading). This allows an observer ofsuch a 2D or 3D image immediately to obtain information in respect ofwhether the building process proceeded in an optimal fashion or whetherthe component may, under certain circumstances, have weaknesses.

The coordinate values localizing the sensor values in the component canbe the build coordinate values used to produce the component. These arethe values which are used to guide the laser beam over the powdersurface and values that represent a Z coordinate in respect of the layernumber. However, it is also possible to newly obtain the coordinatevalues localizing the sensor values in the component when capturing thesensor values, i.e. to scan the component surface to be solidified atthis time using a suitable scanning method and to store values thatcorrespond to a solidification point (point of energy influx into thepowder bed) in the layer. This can be brought about by virtue of thefact that either there is an areal capture of the whole build plane orall that is captured is only a section of interest in the build plane,which contains the component region.

Provision is also made within the scope of the present disclosure forthe sensor values to be captured not directly at the moment of theenergy influx but, additionally or alternatively, offset in timethereafter. By way of example, if the temperature in the melt pool iscaptured at a time TO (during the energy influx) and then at latertimes, e.g. 0.5 seconds, 1 second, 1.5 seconds or the like, it is thenpossible to obtain information about the heat flux in the componentduring the building process from sensor values to be visualized thus inorder, for example, to avoid overheating effects in the case of veryfine component interior regions. By way of example, such time-offsetcapturing methods are referred to as sampling microscope methods inmicroscopy.

In addition to the conventional components of a laser melting apparatuswith a sensor device as per WO 2007/147221 A1, the device for carryingout the method of the present disclosure additionally comprises astorage apparatus, in which the sensor values captured for evaluatingthe component quality are stored together with coordinates localizingthe sensor values in the component, and a visualization apparatus, whichis connected to the storage apparatus and by means of which it ispossible to display the stored sensor values in e.g. a 2D or 3D coloredor grayscale representation in respect of the capture value thereof inthe component.

BRIEF DESCRIPTION OF THE DRAWINGS

The method and apparatus of the present disclosure are explained in moredetail with reference to the figures. In these:

FIG. 1 shows a schematic illustration of a coaxial monitoring processsystem using two vectors as per the prior art;

FIG. 2 shows a schematic illustration of a typical selective laserprocess machine with means according to the present disclosure forcapturing and evaluating the sensor values; and

FIG. 3 shows a flowchart which illustrates essential processes of apreferred method according to the present disclosure.

DETAILED DESCRIPTION

FIG. 1 illustrates a device according to the prior art, wherein thisdevice comprises a method for producing a three-dimensional component 1by a laser melting process. The component 1 is produced by successivesolidifying of individual layers 2 (indicated as dashed line) ofbuilding material 4 which can be solidified by the action of radiation3, by fusing the building material 4. The melt region 5 created by apoint- and/or line-shaped energy influx is captured by a sensor device 6(e.g. camera 11 and photodiode 12) in terms of its dimensions, shapeand/or temperature, and the sensor values resulting therefrom arederived for evaluating component quality.

In the illustrated embodiment of the prior art as per FIG. 1, theradiation 3 is generated by a laser source 7 (laser). It is subsequentlydeflected by a semi-reflective mirror 8 and guided to the layer 2 to besolidified of the building material 4 via a scanner 9 with preferably afocusing lens. The radiation generated at the melt region 5 travels thispath in the opposite direction and passes through the semi-reflectivemirror 8 in a straight line such that said radiation reaches a beamsplitter 10 and there, if deflected, it is guided to a first detector,preferably a camera 11, and, when passing straight through the beamsplitter 6, it is guided to a second detector, for example a photodiode12.

FIG. 2 now illustrates the extension of the system known from the priorart. The component 1 which is assembled on a base plate 14 in the buildregion on a height-displaceable support 13 using said base plate 14 isassembled layer-by-layer (cf layer 2) in the powder bed of the powderybuilding material 4. A deposition apparatus 15 transports the buildingmaterial 4 to the build region from a metering chamber 26.

Proceeding from a laser 7, the radiation 3 is directed at the component1 via the scanner 9 after passing straight through a mirror 16 that canbe passed through from one side. The radiation reflected by thecomponent is guided via the scanner 9 and the mirror 16, which iscompletely reflective in this direction, to a further deflection mirror17 and finally to a detector of a sensor apparatus 6, 11, 12, 18. Thisdetector transmits a signal to a processor 19, preferably amicroprocessor, the output of which reaches a storage medium 20.

The laser 7 is preferably provided with a beam manipulation apparatus21, which for example is designed in the style of a mode aperture, agrating filter or other optical elements. This beam manipulationapparatus 21 is actuated by a controller 22, the control data of which,like the processor data from the processor 19 stored in the storagemedium 20, merge in a data linkage and/or data assignment unit 23. It islikewise possible in the data linkage/data assignment unit 23 to collectand assign to one another control data from the scanner 9 and/or controldata in respect of the height displacement of the support 13, preferablyby means of the actuator 24 thereof. Naturally, it is also possible tosupply to the data linkage/data assignment unit 23 control data from thedepositor of the deposition apparatus 15 and/or of the supply mechanismfor building material for a corresponding component layer 2 (by way ofexample, this could be realized by the control data from the actuator 25of the metering chamber 26). It is also possible for a control module 27of the scanner to be arranged between the scanner 9 and the datalinkage/data assignment unit 23. The data collected in the datalinkage/data assignment unit 23 and assigned to one another (e.g. datatuple) can then be processed further in a further data processing unit28 and/or be visualized via a visualization element 29. It is alsopossible to provide an interface for a data storage medium instead of adata processing unit 28. For example, a monitor, a beamer or a holographcan all be used as visualization element.

Finally, the sensor values captured for evaluating the component qualityare stored together with the coordinate values localizing the sensorvalues in the component 1 and said sensor values are displayed, inrelation to the point of capture in the component 1, in two-dimensionaland/or multidimensional representations by means of the visualizationapparatus 29.

FIG. 3 in an exemplary fashion illustrates an advantageous process ofthe method according to the present disclosure. The process control actson the laser 7 and/or the scanner 9 and regulates the properties of thelaser beam 3 via the laser vector [n]. The building material 4 isexposed proceeding from the scanner 9, as a result of which a melt orthe melt region 5 forms. Radiation is emitted from the melt region 5 andit is detected by the sensor device 6, 11, 12, 18. The result of thisdetection leads to an evaluation (e.g. according to the length, width,area, etc.), leading to temporary storage of the evaluation. Thistemporarily stored evaluation is subjected to so-called mapping. Thismapping is preferably based on definable/modifiable mapping parameters(contrast, color, detector selection, threshold regions, etc.). Postmapping, this is displayed by the visualization apparatus 29 and/orstored. In doing so, it is advantageous if the mapping parameters alsounderlie the storage and/or the representation, i.e. that the mappingparameters are also stored and/or also displayed by the visualizationapparatus 29.

While the method and apparatus of the present disclosure have beendescribed with reference to certain embodiments, numerous modifications,alterations and changes to the described embodiments are possiblewithout departing from the spirit and scope of the present disclosure,as defined in the appended claims. Accordingly, it is intended that themethod and apparatus of the present disclosure not be limited to thedescribed embodiments, but that it has the full scope defined by thelanguage of the following claims, and equivalents thereof.

The invention claimed is:
 1. A method for producing a three-dimensionalcomponent (1) by a laser melting process, the method comprising:producing the three-dimensional component (1) by successivesolidification of individual layers of a powdered building material (4)which can be solidified by the action of radiation, by fusing thepowdered building material (4), creating a melt region (5) within thepowdered building material (4) by a point- and/or line-shaped energyinflux, capturing sensor values from the melt region (5) by a sensordevice (6, 11, 12, 18) for evaluating component quality are derivedtherefrom, generating a component quality output by correlating thesensor values captured from the melt region (5) with the coordinatevalues; and localizing the sensor values in the three-dimensionalcomponent (1); and evaluating the three-dimensional component qualitybased on the component quality output, the component quality outputbeing used to accept, reject, or modify the three-dimensional component;and displaying, by means of a visualization apparatus (29), thecomponent quality output in a two-dimensional and/or multidimensionalrepresentation in respect of the capture location thereof in thethree-dimensional component.
 2. The method as claimed in claim 1,wherein sensor values of the component quality output of a componentplane are displayed in a 2D representation, which sensor valuescorrespond to a layer (2) which is solidified by the action of radiationprior to a new deposition of building material (4).
 3. The method asclaimed in claim 1, wherein sensor values of the component qualityoutput of a freely selectable component sectional plane are displayed ina 2D representation, which plane extends at an angle to a layersuccessively solidified by the action of radiation.
 4. The method asclaimed in claim 1, wherein in a two-dimensional and/or multidimensionalrepresentation, only the component quality output is displayed visuallyand/or highlighted which represent component regions which, compared toat least one definable intended degree of solidification or intendedtemperature value or intended density value, have a deviating, moreparticularly reduced, degree of solidification, temperature value ordensity value or exhibit deviations with respect to an intended energyinflux or intended melt pool dimensions.
 5. The method as claimed inclaim 1, wherein in order to display the the component quality output, asensor value of the component quality representing an optimized valuewith respect to the building material is displayed in a first color, afirst grayscale value, a first degree of transparency and/or with afirst areal structure and values deviating upward or downward from thisoptimized value are displayed differently in terms of color, grayscalevalue, degree of transparency and/or in respect of an areal structure.6. The method as claimed in claim 1, wherein the coordinate valueslocalizing the sensor values in the component (1) at least in part arethe build coordinate values used to produce the component.
 7. The methodas claimed in claim 1, wherein the coordinate values localizing thesensor values in the component (1) at least in part are newly obtainedwhen capturing the sensor values.
 8. The method as claimed in claim 7,wherein the coordinate values localizing the sensor values in thecomponent (1) are obtained by an areal capture of either the whole buildplane or a section of the build plane comprising the component region.9. The method as claimed in claim 1, wherein coordinates are assigned tothe sensor values by means of exposure data or scanner data.
 10. Themethod as claimed in claim 1, wherein the capture of at least some ofthe sensor values takes place with a time delay with respect to the timeof the energy influx and the values of the component quality output aredisplayed by the visualization exhibit a time profile of the thermalbehavior of the melt region.
 11. The method as claimed in claim 1,wherein in respect of the energy influx a plurality of sensor valueswith different time lags from the energy influx are established at oneand the same point in the component plane.
 12. The method as claimed inclaim 1, wherein the three-dimensional component is modified duringsolidification of the powdered building material.
 13. A method forproducing a three-dimensional component (1) by a laser melting process,the method comprising: producing the three-dimensional component (1) bysuccessive solidification of individual layers of a powdered buildingmaterial (4) which can be solidified by the action of radiation, byfusing the powdered building material (4), creating a melt region (5)within the powdered building material (4) by a point- and/or line-shapedenergy influx, capturing sensor values from the melt region (5) by asensor device (6, 11, 12, 18) for evaluating component quality arederived therefrom, generating a component quality output by assigningcoordinates to the sensor values from the melt region (5) by means ofscanner data; correlating the sensor values captured from the meltregion (5) with the coordinate values; and localizing the sensor valuesin the three-dimensional component (1); and evaluating thethree-dimensional component quality based on the component qualityoutput, the component quality output being used to accept, reject, ormodify the three-dimensional component; and displaying, by avisualization apparatus (29), the component quality output in atwo-dimensional and/or multidimensional representation in respect of thecapture location thereof in the three-dimensional component.
 14. Amethod for producing a three-dimensional component (1) by a lasermelting process, the method comprising: producing the three-dimensionalcomponent (1) by successive solidification of individual layers of apowdered building material (4) which can be solidified by the action ofradiation, by fusing the powdered building material (4), creating a meltregion (5) within the powdered building material (4) by a point- and/orline-shaped energy influx, capturing sensor values from the melt region(5) by a sensor device (6, 11, 12, 18) for evaluating component qualityare derived therefrom, generating a component quality output byassigning coordinates to the sensor values from the melt region (5) bymeans of exposure data; correlating the sensor values captured from themelt region (5) with the coordinate values; and localizing the sensorvalues in the three-dimensional component (1); and evaluating thethree-dimensional component quality based on the component qualityoutput, the component quality output being used to accept, reject, ormodify the three-dimensional component; and displaying, by avisualization apparatus (29), the component quality output in atwo-dimensional and/or multidimensional representation in respect of thecapture location thereof in the three-dimensional component.